1. Field of the Invention
The present invention relates to compositions and methods of bonding cord tire reinforcement to the conjugated diene based rubber of tire carcasses and the improved structure obtained thereby.
2. Description of the Prior Art
Tire cord is received from the manufacturer in the form of a fabric. The general practice is to prepare the cord by applying a dip coating of a latex. The dip coating of the cord generally used contains a vinyl pyridine/styrene/butadiene copolymer and a resorcinol-formaldehyde (RF) resin. While these dips are quite effective in performing their desired function, the resorcinol and vinyl pyridine components are expensive and often unobtainable in the quantities needed. In addition, better adhesion would be preferred.
Materials, in addition to RF resins, have been used in the prior art to improve adhesion in special circumstances. For instance, proprietary formulations of unknown composition are marketed for this purpose. In addition, lignin sulfonates are known as replacements for resorcinol in cord dips, see U.S. Pat. Nos. 4,016,119 and 4,026,744 of Elmer, 1977. Also, acrylic acid type copolymers have been used in cord dips, see U.S. Pat. Nos. 2,773,703; 3,364,100 Danielson (1968), 3,367,793 Atwell (1968), 3,408,249 Brown (1968), 3,843,484; and 3,855,168. Also see British Pat. No. 1,256,705 for terpolymers of butadiene and unsaturated dicarboxylic acids.